brown spots, some twisted leaves and some tips curled down

What is your experience level? (first timer, novice, experienced...) Novice - 5 grows

(I only have one plant flowering as of right now)
Your Equipment:
.1) Type and wattage of lights. (MH, HPS, CFL's, tube fluorescents, LED's) - 150w HPS & 2 68w CFL's 2700k
.2) Distance from top? 5inches
.3) Reflector type? (cool tube set-up, bat wing, enclosed reflector, bare bulb...)bat wing
.4) Is there a consistent fresh air supply? yes
.5) Do you have an exhaust fan and a circulation fan? yes
.6) What are the bulb wattages, kelvin ratings, and schedule? (above) schedule is 12/12

Your medium:
.7) Specific brand and type of soil, (coco, peat based soilless...) and anything you've added to it. (vermiculite, perlite, worm castings...) Indoor grow mix mostly coco fiber
.8) Size of container - 10 gallon
.9) Did you use peat pucks (or similar) to root clones or germinate seedlings? no

Your nutrients and water:
10) Source of water? (tap, bottled or filtered) What's it's ph before adjusting? tap, unknown water pH but soil pH is 6.4
11) Method of checking water ph. (ph pen, test strips, aquarium test kit...) n/a
12) Method of adjusting water ph. (phosphoric acid, white vinegar, hydrated lime, PH Up...)n/a
13) Specific brand and N-P-K ratio for each bottle. List dosages (quantity per gallon) and current feeding schedule. Iguana Juice Bloom 4-3-6 & Voodoo Juice
14) How often are you watering between feedings, and how much per watering? once - gallon
15) Any additives or tea's? (Superthrive, CalMag, molasses, Mother's Earth...) no
16) Are your ph levels stable, or do they fluctuate? stable soil pH
17) What is your ingoing water's ph? ...your runoff ph? unknown
18) Do you foliar feed? If so, with what, how often, and at what time do you spray? no

Your growroom:
19) Indoors or outdoors? indoors
20) What size of closet, room or hut? 2 x 5
21) What are the temps and humidity levels while lights are on? ...With lights off? On - 78 degrees w/ 35% humidity Off - 68 degrees w/ 30% humidity (since yesterday. i have been keeping the temperature up when the lights are off but previously this were the readings ^)
22) Have you seen signs of insects in the growroom? no but have lady bugs

Your strain:
23) What strain are you growing? (Indica dominate or Sativa dom?) sativa dominant
24) From seeds or clones? seeds
25) Is this an autoflower strain? no

well i hope this helps with determining the problem

the nutrient feeding is 16 mL per gallon and feeding once a week.

any ideas :/